English
fanwank
From fan + wank.
Proto-Indo-European *h₂weh₁- ‘to blow’
Latin vannus ‘fan for winnowing grain’
Old English fann ‘a winnowing fan’
Middle English fan
English fan
The story
British writer Craig Hinton claimed to have coined the term in the context of Doctor Who fandom.
Today it means
noun Explanations invented by fans (of a film franchise, television series, etc.) to gloss over mistakes in continuity.
Language periods are conventional ranges, not dates for this word.
Etymograph / fanwank